<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script>
        // 编写函数has(arr , 60) 判断数组中是否存在60这个元素，返回布尔类型 var arr = [1, 2, 3, 60] var arr2 = [1, 2, 3]

        function has(a,b) {
            if(a.indexOf(b)!=-1){
                // document.write("有")
                return true;
            }else{
                // document.write("无")
                return false;
            }
        }

        var arr = [1, 2, 3, 60]; 
        var arr2 = [1, 2, 3];
        console.log(has(arr, 60)) // true
        console.log(has(arr2, 60)) // false

    </script>
</head>

<body>

</body>

</html>